thanks you both dtengineering and Gdeaver, for your replies.
dtengineering,
about the voltage, the PICs and the motors are fed seperatly,
so no worries here.
and I know there are alternatives for the R\C sysytem,
but, I already have one, it's handy, easy, and I have experience with it.
so, no worries here as well, (money IS an issue

).
GDEAVER, thanks you,
I'm not getting near using full load,
actually, I'm working right now, choosing the best waveform to send to the motor driver.
It
WON'T BE PWM, but something very similiar.
Ran.
Edit:I thought of sending the motor-driver, a pulse of 10mS, every 30mS, ("1" for 10mS, then "0" for 20mS).
so it won't have long peak times, nor motor-grinding-quick changes.
I used
that as a reference, what do you think?